Biocompatible polymers have been used to prepare polymeric matrices that can be associated with, or formed into, implantable medical devices. For example, biocompatible polymers can be used to make a coating on the medical device's surface.
Polymeric surface coatings can provide medical articles, such as those that are implanted or temporarily inserted into the body, with a variety of distinct benefits. These benefits include lubricity and wettability, passivity against protein absorption, antimicrobial properties, drug delivery, biocompatibility, and hemocompatibility. The demand for medical articles having these types of coatings has appreciated because they generally improve the function of the device upon implantation or insertion in the body. For example, a lubricious polymeric coating may have properties which reduce frictional forces when the device is introduced and moved within the body. Various catheter types are examples of medical articles that may be provided with hydrophilic coatings. Hydrophilic coatings are generally known in the art of implantable medical devices.
Detection of the coatings applied to an implantable medical device can be useful during the manufacturing process to detect the thickness and uniformity of the coating, as well as the completeness of coverage of the device by the coating. Many coatings applied to an implantable medical device are transparent and otherwise difficult to detect. Reagents such as colorants and dyes can be added to the coating polymer to make the coating visually detectable when applied to the device. However, these reagents can leach from the polymeric coating before, during, and after implantation.